I was doing some late night surfing and saw a note you posted on the old FE forum, and so I now found your new MEL forum. I’m posting some info here, and I am also linking my ChrisCraftCommander.com form to yours.
The marine 431 MEL motor was used by Chris Craft beginning in the late 1950s or early 1960’s, not sure when the first one was used, but they were used in the big premium wood runabouts like the Chris Craft Continental and many of their premium wood cruisers of the era.

Here is a scan of some original literature I purchased on ebay, and you are welcome to use it here on your forum. My intent is to share the info.

In 1966 Chris Craft transitioned from the MEL to the FE, so there were two years of use in the premium fiberglass Commander too. They were fine motors, many still in operation. Where torque is really the issue, the MEL did fine, as marine motors rarely run over 4000 rpm. Many big cruisers use a 2.5:1 gear reduction Paragon transmission, and are swinging props of 22 to 24 inches in diameter.

Here is a link to an article I scanned about the first Chris Craft Commander of 1964, which was their first fiberglass cruiser. It was powered with a pair of MEL 431 motors and it received wide acclaim for performance. You can see how a pair of MEL motors would push a 20,000 pound boat at 31 miles per hour!http://www.network54.com/Forum/424840/m ... 1191346702

The interesting thing I have noted is that Chris Craft continued to use MEL engines after they were discontinued in cars. For someone looking for a good MEL consider finding an old marine block... usually low hours relative to age. The cam would be different.

MEL Marine division... and if you thought MEL car parts were scarce....

At only 8.0:1 compression ratio and that many cubes, I'll bet that thing sounds totally unique on the water, especially with the stancard unmuffled copper wet exhaust system.

Chris Craft used many Hercules flathead motors of various sizes, some small and some very large, but they were all heavy iron with low compression, and as a result they lasted forever. The marine MEL with that low compression would be a very durable chunk of American iron. In addition, it is actually a musical instrument. Bet it sure sounds great when docking, ha!